Flexible Uplink MU-MIMO Scheduling in UnlicensedSpectrum

• Published in: 中国通信：英文版 Vol. 14; no. 12; pp. 59 - 71
• Main Author: Boqi Jia;Ting Zhou;Honglin Hu;Yang Yang;Zhenhong Li;Sandrine Boumard
• Format: Journal Article
• Language: English
• Published: 2017
• Subjects: 5G;;unlicensed;spectrum;MU-MIMO;;uplink;scheduling
• ISSN: 1673-5447

Utilizing the unlicensed spectrumas supplementary is being studied to meetthe increasingly growing demand of userequipment for rate, traffic and bandwidth, andthus to mitigate the current spectrum scarcitycrisis. In this paper, we investigate the uplinkmulti-user multiple-input multiple-output（UL MU-MIMO） technique to achieve multi-plexing gain in unlicensed spectrum. We firstdefine a new parameter called channel busyradio （CBR） which is related to the probabil-ity of occupying the unlicensed channel, and nd that the failure to occupy the unlicensed：hannel leads to the performance degradationin unlicensed spectrum. Then, according to theaser-specific CBR of the unlicensed channel,e propose a flexible scheduling scheme forUL MU-MIMO in unlicensed spectrum, and[ormulate an optimization problem for the3primal scheduled user number. Furthermore,ul adaptive scheduling algorithm is proposed：o decide the optimal number of the scheduledJsers efficiently. The simulation results show：hat, based on statistical channel condition inanlicensed spectrum, adjusting the number3f the scheduled user flexibly can offset thedegraded throughput and form an optimalMU-MIMO transmission.